1 /*
   2  * Copyright (c) 2003, 2006, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 # include "incls/_precompiled.incl"
  26 # include "incls/_constMethodOop.cpp.incl"
  27 
  28 // Static initialization
  29 const u2 constMethodOopDesc::MAX_IDNUM   = 0xFFFE;
  30 const u2 constMethodOopDesc::UNSET_IDNUM = 0xFFFF;
  31 
  32 // How big must this constMethodObject be?
  33 
  34 int constMethodOopDesc::object_size(int code_size,
  35                                     int compressed_line_number_size,
  36                                     int local_variable_table_length,
  37                                     int checked_exceptions_length) {
  38   int extra_bytes = code_size;
  39   if (compressed_line_number_size > 0) {
  40     extra_bytes += compressed_line_number_size;
  41   }
  42   if (checked_exceptions_length > 0) {
  43     extra_bytes += sizeof(u2);
  44     extra_bytes += checked_exceptions_length * sizeof(CheckedExceptionElement);
  45   }
  46   if (local_variable_table_length > 0) {
  47     extra_bytes += sizeof(u2);
  48     extra_bytes +=
  49               local_variable_table_length * sizeof(LocalVariableTableElement);
  50   }
  51   int extra_words = align_size_up(extra_bytes, BytesPerWord) / BytesPerWord;
  52   return align_object_size(header_size() + extra_words);
  53 }
  54 
  55 
  56 // linenumber table - note that length is unknown until decompression,
  57 // see class CompressedLineNumberReadStream.
  58 
  59 u_char* constMethodOopDesc::compressed_linenumber_table() const {
  60   // Located immediately following the bytecodes.
  61   assert(has_linenumber_table(), "called only if table is present");
  62   return code_end();
  63 }
  64 
  65 u2* constMethodOopDesc::checked_exceptions_length_addr() const {
  66   // Located at the end of the constMethod.
  67   assert(has_checked_exceptions(), "called only if table is present");
  68   return last_u2_element();
  69 }
  70 
  71 u2* constMethodOopDesc::localvariable_table_length_addr() const {
  72   assert(has_localvariable_table(), "called only if table is present");
  73   if (has_checked_exceptions()) {
  74     // If checked_exception present, locate immediately before them.
  75     return (u2*) checked_exceptions_start() - 1;
  76   } else {
  77     // Else, the linenumber table is at the end of the constMethod.
  78     return last_u2_element();
  79   }
  80 }
  81 
  82 
  83 // Update the flags to indicate the presence of these optional fields.
  84 void constMethodOopDesc::set_inlined_tables_length(
  85                                               int checked_exceptions_len,
  86                                               int compressed_line_number_size,
  87                                               int localvariable_table_len) {
  88   // Must be done in the order below, otherwise length_addr accessors
  89   // will not work. Only set bit in header if length is positive.
  90   assert(_flags == 0, "Error");
  91   if (compressed_line_number_size > 0) {
  92     _flags |= _has_linenumber_table;
  93   }
  94   if (checked_exceptions_len > 0) {
  95     _flags |= _has_checked_exceptions;
  96     *(checked_exceptions_length_addr()) = checked_exceptions_len;
  97   }
  98   if (localvariable_table_len > 0) {
  99     _flags |= _has_localvariable_table;
 100     *(localvariable_table_length_addr()) = localvariable_table_len;
 101   }
 102 }
 103 
 104 
 105 int constMethodOopDesc::checked_exceptions_length() const {
 106   return has_checked_exceptions() ? *(checked_exceptions_length_addr()) : 0;
 107 }
 108 
 109 
 110 CheckedExceptionElement* constMethodOopDesc::checked_exceptions_start() const {
 111   u2* addr = checked_exceptions_length_addr();
 112   u2 length = *addr;
 113   assert(length > 0, "should only be called if table is present");
 114   addr -= length * sizeof(CheckedExceptionElement) / sizeof(u2);
 115   return (CheckedExceptionElement*) addr;
 116 }
 117 
 118 
 119 int constMethodOopDesc::localvariable_table_length() const {
 120   return has_localvariable_table() ? *(localvariable_table_length_addr()) : 0;
 121 }
 122 
 123 
 124 LocalVariableTableElement* constMethodOopDesc::localvariable_table_start() const {
 125   u2* addr = localvariable_table_length_addr();
 126   u2 length = *addr;
 127   assert(length > 0, "should only be called if table is present");
 128   addr -= length * sizeof(LocalVariableTableElement) / sizeof(u2);
 129   return (LocalVariableTableElement*) addr;
 130 }